In recent years a number of procedures have been proposed for producing meat analogs from vegetable protein materials, particularly soybeans. Typically such meat analogs are produced by passing an aqueous soy flour slurry through an extrusion cooker under predetermined conditions of moisture, time, temperature and pressure to form an expanded product, or by spinning an aqueous protein isolate slurry into fibers. Recently the use of steam as a texturizing agent has been proposed to produce texturized soy protein pieces intended to simulate meat products.
Such prior procedures have not been entirely satisfactory, however, since the texturized protein products produced lack the texture, appearance, physical structure and mouthfeel of natural meat. For example, meat analogs produced by steam texturizing soy protein have a texture and appearance similar to cooked ground beef rather than that of striated or skeletal muscle tissue. Prior procedures have been unable to impart to texturized protein products the texture, appearance and physical structure of natural meat pieces. This inability to produce texturized vegetable protein which simulate chunks of natural meat is a primary reason for the lack of widespread consumer acceptance of currently available meat analog products. In addition, prior procedures typically have employed such complex equipment and operations that production costs have made the resulting meat analog products commercially unattractive, despite the relatively inexpensive nature of the starting material.